1. Field of the Invention
This invention relates to a separable slide fastener, and more particularly to a separable bottom-end-stop assembly of synthetic resin which is in the form of a three-member structure composed of a box, a box pin and an insertion pin and in which the box can be threaded onto one of a pair of opposite fastener stringers after sewing.
2. Description of the Related Art
A separable bottom-end-stop assembly for a separable slide fastener is known which is in the form of a three-member structure composed of a box 1', a first pin 2' to be received in the box 1', and the second pin 3', in which the box 1' can be attached to the box pin 2' after sewing. The box 1' has front and back walls 7', 8' bridged by a central partition 6' to define first and second pin insertion bores 4', 5' one on each side of the partition 6'. The central partition 6' has a projection for pressing the inserted first pin 2' against one side wall. The front and back walls 7', 8' have projections to be received in the respective recesses in front and back surfaces of the first pin 2'. Thus the box 1' and the first pin 2' are fixedly attached to the bottom end portions of opposite fastener stringers S. (See Japanese Utility Model Publication No. Sho 63-33530 and FIG. 9 of the accompanying drawings.)
Also known is a three-member separable bottom-end-stop assembly, for a concealed separable slide fastener, which comprise a box 1" and first and second pins 2", 3", in which the box 1" can be attached to the first pin 2" after sewing. The box 1" has on its side wall an resilient locking tongue 9" designed to catch a hook 19" on the tip of the first pin, thus fixedly attaching the box 1" and the first pin 2" to one of opposite slide fasteners S. (See Japanese Patent Laid-Open Publication No. Hei 6-46906 and FIG. 10 of the accompanying drawings.)
The conventional separable bottom-end-stop assembly for a separable slide fastener is designed to have the first pin locked into the box, either by clenching the box over the first pin or by fusing the box and the first pin together, after the first pin is inserted into the box. Since the box is attached to one of opposite fastener stringers before sewing to a garment, the sewing work is obstructed. It is also very difficult to manufacture a small-sized separable bottom-end-stop assembly to fit a narrow slide fastener, which durability is too poor for its production.
In the first-named conventional separable bottom-end-stop assembly, the projection 9' on the central partition 6' of the box 1' merely projects toward the first pin insertion bore 4' and does not serve to lock the first pin 2'. Actually the first pin 2' is secured by the projections 10' on the inner walls of the box 1' which are received in the corresponding recesses on the front and back side surfaces of the first pin 2'. Therefore, in the event the fastener stringers S are moved laterally along the inner longitudinal margin, the first pin 2' is vulnerable to laterally sway inside the first pin insertion bore 4'. Also, the resilient projections 9' on the central partition 6' allow the first pin 2' to get loosen, thereby causing the box rattle to make the whole unit nonstable.
The second-named conventional separable bottom-end-stop assembly is designed for a concealed slide fastener and therefore is not universally applicable to ordinary slide fasteners. Moreover, the hook 20" on one side of the first pin 2" is engageable with the locking strip on the central partition 6" of the box 1". Further, the first pin 2" has another hook 19" engageable with the corresponding locking tongue 9" on the side wall of the box 1" so that the box 1" and the first pin 2" are secured to each other under normal conditions. When opposing force is applied between the box 1" and the fastener stringers S, however, the locking tongue 9" comes off the hook, so that the hook 20" comes into engagement with the locking strip on the central partition 6". Thus, the first pin 2", though not coming off the box 1", is held sufficiently stable in the box 1.